Fish Lake
Fish Lake in Jackson County, Minnesota has a water quality grade of C (Fair). Water clarity: 4.5 ft visibility. Phosphorus: 45.5 µg/L. Chlorophyll-a (algae): 13.1 µg/L.
- Clarity
- 4.5 ft
- Typical in August
- 76°F
- Max depth
- ~32 ft est.
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
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Fish Lake is a productive, nutrient-rich eutrophic lake in Jackson County, Minnesota with an estimated average depth of about 32 feet. Water quality is graded C based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings. Compared to the 5 other monitored lakes in Jackson County, Fish Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyModerate
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 4.5 ft. Phosphorus level: 45.5 µg/L. Chlorophyll-a: 13.1 µg/L. Trophic State Index: 57.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.5 ft | Not graded |
| Phosphorus | 45.5 µg/L | Fair |
| Chlorophyll-a (Algae) | 13.1 µg/L | Good |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Fish Lake
Compare lakeside cabins, hotels, and vacation rentals near Fish Lake in Jackson County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Water Temperature
Fish Lake typically sits around 76°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 77°F) and coldest in Apr (about 52°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 402 field readings (2022–2025) via the EPA Water Quality Portal. See the full Fish Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Fish Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was very high (1,018,591 cells/mL) on July 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Fish Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Public Water Access Sites — Fish (Main Lake)Public Water Access Sites · MN DNR LakeFinder
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~32 ft est. |
| Average Depth | ~12 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Fish Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Fish LakePublic
- Summit LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Fish Lake
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.101 m/yr | 6 |
| Phosphorus | ↓ Declining | +4 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -1.9 µg/L/yr | 2 |
EPA Impairment Status
Fish Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN32-0018-03 · Official waterbody report · Matched by proximity (0.03 km)
County Ranking
Ranked #1 of 6 lakes in Jackson County
Nearby Lakes in Jackson County
Frequently asked questions about Fish Lake
Where is Fish Lake?
- Fish Lake is a lake in Jackson County, Minnesota. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Fish Lake?
- Fish Lake in Jackson County, Minnesota has a water quality grade of C (Fair). Water clarity: 4.5 ft visibility. Phosphorus: 45.5 µg/L. Chlorophyll-a (algae): 13.1 µg/L.
Is Fish Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Fish Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 13.1 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Fish Lake?
- Fish Lake typically sits around 76°F at the surface in August, from 402 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.
How deep is Fish Lake?
- No published bathymetric survey covers Fish Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 32 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Does Fish Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Fish Lake (clouds, ice, or an off-season gap). The most recent reading was very high (1,018,591 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Fish Lake?
- Fish Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Fish Lake, Summit Lake. Public access is listed as yes.
Explore Fish Lake across LakeQuality
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
536 measurements from 4 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA536 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (4)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory